I'm guessing, judging by the rock formation, that the water level of the pool used to be at the height of the roof so the water didn't need to fall at all.

What happened? Global warming?

Or someone pulled the plug out?

No, the Pool is at the end of a box canyon. The waterfall has worked its way up the Hamilton Creek (which is what feeds the waterfall). The pool is the result of several forms of erosion.

What happened was that for many tens of millions of years, this area was inundated under an arm of what became the Atlantic Ocean. Called the Niobrara Sea, or Western Interior Seaway, this massive body of water would inundate and recede from the continental interior. When the area was undersea, thick beds of limestone were laid down. When it was exposed to the air, the atmosphere laid down thin layers of topsoil.

Around the end of the Cretaceous, the sea receded finally and didn't return.

Erosion then took over, with rainwater leaching through the limestone and dissolving soluble minerals in both the limestone and the thin layers of topsoil, leaving these great slabs of limestone weakened. That same water also eroded the shale under the limestone, further robbing it of support. About 100,000 years ago, a sinkhole (I almost typed "sinhole", lol) opened up under where the grotto is today, and that brought the limestone down with it.

In major flood events it can get pretty full. In October of 2013, the area got 7" of rain in one day. The water level rose about 15 feet, and we were closed for three weeks for repairs. I doubt it has ever been filled to the brim in historical times, though.

I'm guessing, judging by the rock formation, that the water level of the pool used to be at the height of the roof so the water didn't need to fall at all.

What happened? Global warming?

Or someone pulled the plug out?

No, the Pool is at the end of a box canyon. The waterfall has worked its way up the Hamilton Creek (which is what feeds the waterfall). The pool is the result of several forms of erosion.

What happened was that for many tens of millions of years, this area was inundated under an arm of what became the Atlantic Ocean. Called the Niobrara Sea, or Western Interior Seaway, this massive body of water would inundate and recede from the continental interior. When the area was undersea, thick beds of limestone were laid down. When it was exposed to the air, the atmosphere laid down thin layers of topsoil.

Around the end of the Cretaceous, the sea receded finally and didn't return.

Erosion then took over, with rainwater leaching through the limestone and dissolving soluble minerals in both the limestone and the thin layers of topsoil, leaving these great slabs of limestone weakened. That same water also eroded the shale under the limestone, further robbing it of support. About 100,000 years ago, a sinkhole (I almost typed "sinhole", lol) opened up under where the grotto is today, and that brought the limestone down with it.

In major flood events it can get pretty full. In October of 2013, the area got 7" of rain in one day. The water level rose about 15 feet, and we were closed for three weeks for repairs. I doubt it has ever been filled to the brim in historical times, though.

How do you know all that? Were you there?

Or to put it another way ...

you're in Texas, right? How do you explain all that to visitors who believe that the planet is only 6,000 years old?

"And this beautiful rock formation was designed by god as the Nephilim's bidet"

(25-07-2015 12:05 PM)Thumpalumpacus Wrote: ...
Never mind, I didn't realize you wanted a set-up for a cheap joke. You have a good day now.

Whoa noes! I was being serious.

Those are beautiful shots of a beautiful place. It stands to reason that it would attract many visitors. I zoomed in to the first one and could see people and a walkway (which, btw, was a good photographic choice in order to give an idea of scale).

This led me to the realisation that this nature preserve (incidentally, other countries have nature 'reserves' ... 'preserve' is a better term, I think) is open to the public which means there might be guided tours and/or plaques or signs along the way and/or a visitors centre where people park up before setting off on their hikes and maybe a gift shop, restaurants etc.

So then it crossed my mind ... hang on! That's in Texas. That's bible country! A proportion of visitors are bound to be Young Earth Creationists!

So there you are (there one is), a responsible and broad-minded parent who has a passion for nature and wants your children to experience first-hand the wonder of nature / god's creation so you plan a day trip to the national park and all goes well until you notice signs (or your guide explains) that 100,000 years ago a sink-hole ... wait! What!?!?

Perhaps it's just my imagination running loose but am I wrong? and if not, the visitors' centre will have a complaints register:
"Dear sir/madam, how dare you teach lies to my children etc. etc. 100,000 years!!! How do you know? Were you there?!?!?!?!"

Equally, if there are no complaints, what is that telling us? That YECs don't visit nature preserves? That they do but don't complain? That they don't really believe what they are taught to believe?

Thump, by all means give me a thump for using a flippant tone regarding something about which you are passionate (I'm OK with being thumped) but also please note that the underlying point held a serious question.

Cheers.

ps, on a personal note, in my youth, sitting, lost in thought, by a waterfall in the height of summer in the Derbyshire Dales is probably the closet I've ever come to 'spiritual'.

When I was studying in Hangzhou, some of my classmates and I took a train up to Inner Mongolia (China) then went on an extended horseback riding trip into Outer Mongolia. We brought a bunch of apples as gifts because we'd heard that some of the younger kids, who grew up impoverished after the collapse of the Soviet Union and the subsequent collapse of many of its trade routes into Mongolia, had never even tasted fruit before. So when we stopped in a village, we let them try apples and they let us try goat blood soup lol. Good times...

Sorry if I slightly derailed the thread with the bout of nostalgia that picture inspired